Flame resistant material



Dec. 17, 1957 R. P. LAPPALA l 2,816,415

FLAME RESISTANT MATERIAL Filed sept. 22,' 1954.

- INVENTOR. R/S'O l? LAPPALA Alfarney BY/4 MM.

United States Patent i FLAME RESISTANT MATERIAL Risto P. Lappala, Madison, Wis., assignor to Bjorksten Research Laboratories, Inc., Madison, Wis., a corporation of Illinois Application September 22, 1954, Serial No. 457,625

12 Claims. (Cl. 57-145) This invention relates to a liexible woven material adapted to resist heat and to serve as a material from which fire-resistant aircraft crash rescue suits may be made.

Such suits have had two primary disadvantages: They have been inadequately fiexible or they have had inadequate resistance to high temperatures.

It is therefore an object of this invention to provide a woven iiexible material having extremely high resistance to temperatures on the order of 2000 F.

Another object is a iieXible material comprising refractory materials incorporated in a woven wire structure.

Further objects will become apparent from the drawings and the following detailed description in which it is my intention to illustrate the applicability of the invention without thereby limiting its scope to less than all those equivalents which will be apparent to those skilled in the art. In the drawings like reference numerals refer to like parts and:

Figure 1 s a perspective diagrammatic view showing the forming of a strand of substantially refractory material;

Figure 2 is a top view of a Woven fabric having incorporated therein the strands of Figure l;

Figure 3 is a perspective diagrammatic view of the formation of another embodiment of the strand of Figure 1; and

Figure 4 is a cross-sectional view of a strand formed as in Figure 3.

Aluminum oxide containing material has been produced in fibrous forms by the Carborundum Company. The resultant fibrous product is sold under the trade name Fiberfrax. The fibers are too short to permit spinning in order to form yarn therefrom but it has been found that they may be formed into a mat resembling heavy blotting paper by utilizing conventional paper making machinery.

A paperlike mat made from Fiberfrax was obtained from Hurlburt Paper Company. This material had a thickness of 0.05 inch and density of 6.5 oz./yd.2

The inventor also prepared paperlike mats from Fiberfrax, utilizing the Fourdrinier machine at the Forest Products Laboratory, Madison, Wisconsin. A small quantity of extremely fine short glass fiber, often referred to as frogs hair, sold by Owens-Corning Fiberglas Company and designated AAA by said company was incorporated in some of these mats.

Percent AAA Thickness Density, fiber incorpo oz./yd.2 rated in paperlike mat The glass fiber provided material with better tensile strength and better reiiectivity. As shown in Figure .l a strand 1 of substantially refractory material was formed by folding (as at 3) a strip 2 of the Fiberfrax paperlike mat lengthwise, laying ametals wine 4i into-thefoldtand then. furthery folding the. strip.. (as. at. and 'uginding,l a strand. 6.0i( glass, wirefor. metal .ribbonaroundt the doubly folded paper and the wire core. The refragtony, strands lfthus-produced weregutilizedcas iiliingiupnepariflgfabric with box weaves, twill weaves andi satin. V.vvgaesW113i@- in the warp consisted of nickel-chromium resistance Wire (Nichrome) in some cases and Inconel Wire in others and wherein in some cases the yarn prepared as shown in Figure l was alternated as filling with Refrasil yarn (H. I. Thompson Company) plied with a single strand of Nichrome or Inconel wire.

A preferred embodiment is illustrated by Figure 2 wherein is shown a box weave fabric having a wire warp 7 and alternate picks of refractory yarn 1 and Refrasil yarn 8. The fabrics thus produced are listed below:

Warp Fill Fiberfrax Ends Warp Material Ends Refrasil Filling Weave per in. per in fill inch 16 #36 Nichrome 6 3 3 Plain Wire (or In- (Box).

3 (plied with Box.

wire). 3 harness satin. 16 ..do 3-4 0 3-4 twill.

Each of the fabrics thus produced was exposed fortfvc minutes to a flame having a fiame temperature of 2,000

F. The temperature on the sides of the fabrics opposite from the flame varied from 850 F. to 950 F. p

As shown in Figures 3 and 4 the strip of refractory mat 2 may be folded only once longitudinally (as at 9)y instead of being folded twice in the manner of Figure i.

It has not been possible heretofore to utilize the unique qualities of aluminum oxide containing fiber such as Fiberfrax in a flexible material. This material has not been incorporated heretofore in a woven material.

Thus it may be seen that the invention is broad in scope and is not to be limited excepting by the claims.

Having thus disclosed my invention, I claim:

1, A refractory strand comprising a strip of paperlike mat comprising fibers made of a mixture comprising aluminum oxide, said strip being folded longitudinally and provided with a wire core and held in place by heatresistant strands wrapped therearound.

2. A woven material comprising the strands of claim 1 as filling.

3. Woven material comprising the strands of claim l as filling and wire as warp.

4. A strand of a predominantly refractory material comprising a longitudinally folded strip of a paperlike mat made from fibers made of a mixture comprising aluminum oxidedand glass fibers having a wire core disposed within said fold and held in said folded form by a metallic wirelike member wrapped therearound.

5. Woven fabric comprising the strands of claim 4 as filling.

6. Woven fabric comprising the strands of claim 4 as filling and wire as warp.

7. A refractory strand comprising a strip of paperlike mat comprising fibers made of a mixture comprising aluminum oxide, said'strip being folded longitudinally and provided with a core comprising at least one heatresistant strand and held in place by at least one heatresistant strand wrapped therearound.

8. A woven material comprising the strands of claim 7 as filling.

9. Woven material comprising the strands of claim 8 as filling and wire as warp.

10. A refractory strand comprising a strip of paperlike mat comprising fibers made of a mixture comprising aluminum oxide, said strip being folded longitudinally and provided with a wire core and held in place by at least one heat-resistant strand wrapped therearound.

1l. A woven material comprising the strands of claim 10 as lling.

12. Woven material comprising the strands of claim 10 as filling and wire as warp.

References Cited in the le of this patent UNITED STATES PATENTS 

1. A REFRACTORY STRAND COMPRISING A STRIP OF PAPERLIKE MAT COMPRISING FIBERS MADE OF A MIXTURE COMPRISING ALUMINUM OXIDE, SAID STRIP BEING FOLDED LONGITUDINALLY 